U.S. patent number 4,696,626 [Application Number 06/827,848] was granted by the patent office on 1987-09-29 for railroad car air compressor unit.
This patent grant is currently assigned to Nippon Air Brake Co., Ltd.. Invention is credited to Yasuhisa Hata, Takeshi Hatimaki, Satoshi Ogura.
United States Patent |
4,696,626 |
Hata , et al. |
September 29, 1987 |
Railroad car air compressor unit
Abstract
A compact, balanced and lightweight air compressor unit for a
railroad vehicle which includes a motor-driven compressor, a
suction strainer and suction silencer. The compressor and motor are
interconnected by an intermediate hollow flanged mounting member
which has a cross-sectional dimension that is smaller than the
cross-sectional dimension of the motor and compressor. The suction
strainer is located in a space between the motor and compressor and
is attached to one side of the intermediate hollow mounting member
while the suction silencer is located in a space between the motor
and compressor and is attached to the other side of the
intermediate hollow mounting member to form a substantially
balanced structure which is suspended to the underside of the floor
of the railroad vehicle by a plurality of resilient bumper
connectors.
Inventors: |
Hata; Yasuhisa (Akashi,
JP), Hatimaki; Takeshi (Akashi, JP), Ogura;
Satoshi (Kobe, JP) |
Assignee: |
Nippon Air Brake Co., Ltd.
(Kobe, JP)
|
Family
ID: |
11944953 |
Appl.
No.: |
06/827,848 |
Filed: |
February 7, 1986 |
Foreign Application Priority Data
|
|
|
|
|
Feb 8, 1985 [JP] |
|
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60-17472[U] |
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Current U.S.
Class: |
417/312; 417/313;
417/363 |
Current CPC
Class: |
B61D
27/00 (20130101); F04C 29/06 (20130101); F04C
23/00 (20130101) |
Current International
Class: |
B61D
27/00 (20060101); F04C 29/06 (20060101); F04C
23/00 (20060101); F04B 039/16 () |
Field of
Search: |
;105/1.3,138,139
;417/312,313,363 ;62/296 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Leonard E.
Attorney, Agent or Firm: Sotak; J. B.
Claims
We claim:
1. A motor-driven air compressor unit for a railroad vehicle
comprising, an intermediate hollow mounting member having an outer
diameter which is smaller than the outer diameter of the motor and
the compressor, said intermediate hollow mounting member has an
open flange formed on one end, a matching section formed on one end
of the motor so that the compressor is connectable to the motor,
the drive shaft of the motor and the crank shaft of the compressor
are coupled by a coupling located inside of the intermediate hollow
mounting member, and a suction filter and a suction muffler are
connected to each other by a connecting line, the suction filter is
located in a space formed on one side of the outer surface of the
intermediate hollow mounting member and adjacent the ends of the
motor and the compressor, the suction muffler is located in a space
formed on the other side of the intermediate hollow mounting member
and adjacent the ends of the motor and the compressor, and the
motor and the compressor are suspended beneath the floor of the
railroad vehicle by a pair of suspension pieces which are isolated
by vibration-absorbing members.
2. The motor-driven compressor unit according to claim 1, wherein
one of the pair of suspension pieces is attached to the top of the
motor.
3. The motor-driven air compressor unit, according to claim 1,
wherein the motor, the compressor, the suction filter, and the
suction muffler form a balanced structure to reduce the adverse
effects of the vibrational forces.
4. The motor-driven compressor unit, according to claim 1, wherein
each of the vibration-absorbing members takes the form of a
resilient dampening bumper.
5. The motor-driven air compressor unit, according to claim 4,
wherein the other of the pair of suspension pieces is attached to
the top of the air compressor.
Description
FIELD OF THE INVENTION
This invention relates to an air compressor unit for a railroad car
which is suspended under the railroad car floor and which is
equipped with a suction dust filter, a suction muffler, and a
compressor which is driven by an electric motor.
BACKGROUND OF THE INVENTION
A railroad car air compressor unit of the prior art is explained in
greater detail with reference to FIGS. 2a, 2b, and 2c, which
illustrate a side elevational view, a top plan view, and a
schematic flow diagram, respectively, of a motor-compressor unit in
accordance with the prior art. As shown, a railroad car air
compressor unit 1 is suspended underneath the floor 2 of the
railroad car and includes an electric motor 3, a compressor 4, a
dust suction filter 5, a suction muffler 6, and a base frame 30
which supports and carries the motor, compressor, etc., and four
suspension pieces 31 which suspend the base frame 30. The electric
motor 3 is located and fixed on one side of the base frame 30 by a
plurality of base support members 32. The compressor 4 is located
and fixed on the other side of the base frame 30 by another
plurality of base support members 32. The rotating shaft 13 of the
electric motor 3 and the crank shaft 16 of the compressor 4 are
connected via coupling member 17. The outside of this coupling
member 17 is covered by the protective cover 33 which is made of a
metal mesh which can readily dissipate the heat and which is fixed
in a suitable manner to the base frame 30 for safety purposes.
The suction dust filter 5 and the suction muffler 6 are located on
one of the sides of the electric motor 3 as a sinlge piece unit,
while the terminal box 34 and inspection hatch 35 are located on
the other side of the motor. In this type of construction, the air
for the compressor 4 comes through the suction dust filter 5 and
the suction muffler 6 is divided into the suction inlets 37 of two
low-pressure cylinders 36 for pressurization. This pressurized air
is then emitted from the outlet 38 of the low-pressure cylinder 36
to the inlet 40 of a middle cooler 39. The cooler 39 is installed
at the underside of the base frame 30 so that it releases the heat
and is effectively cooled down by the surrounding air. The air is
then conveyed from the outlet 41 of the middle cooler 39 to the
inlet 43 of the high-pressure cylinder 42 and is further compressed
to a higher level. The compressed air from the outlets 44 is
connected to a common pipe which leads to the back cooler, not
shown in FIGS. 2a, 2b, and 2c.
The four suspension pieces 31 are connected, such as by welding, to
the base frame 30 at their lower ends so that the base frame 30 is
suspended from each of the four corners thereof. Their upper ends
are fixed to the underside of the floor of the cars by suitable
bolts or nuts which cooperate with vibration-proof flexible washers
or rubber or neoprene dampening mounts 21.
In such an arrangement, the compressor 4 is driven by the motor 3
through the rotation of the rotating shaft 13 which movement is
transferred to the crank shaft 16 by the coupling member 17. Thus,
the low-pressure cylinder 36 and the high-pressure cylinder 42 are
operated, and the air which is sucked in passes through the suction
dust filter and the suction muffler. The air is then conducted to
two low-pressure cylinders and also to two high-pressure cylinders
in the direction shown by the arrows in FIG. 2c so that the air is
effectively compressed.
It will be appreciated that any dust in the atmosphere is filtered
by the suction dust filter 5 to prevent excessive wear to the
compressor 4, and the suction sound of the compressor 4 is masked
by the suction muffler 6. The vibration which comes from the
compressor 4 and/or the electric motor 3 is decreased by the
vibration-proof flexible washer dampeners or rubber bumpers 21.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood by reference to the
following portion of the specification when taken in conjunction
with the accompanying drawings in which:
FIGS. 1a, 1b, and 1c illustrate a side elevational view, a top plan
view, partly in section, and a partial sectional view taken along
lines A--A of FIG. 1a, respectively, of a preferred embodiment of
the present invention.
FIGS. 2a, 2b, and 2c illustrate a side elevational view, a top plan
view, and a schematic flow diagram, respectively, of a
motor-compressor unit in accordance with the prior art.
Generally, the railroad car air compressor unit 1 is suspended from
underside of the car floor 2 which has a very limited amount of
available space. In most cases the unit is required to be light in
weight and to be compact in shape. Based on such requirements, the
base frame 30 of the unit 1 of the prior art is designed to have
the necessary minimum area to readily permit the fixation or
mounting of the electric motor 3 and the compressor 4. Therefore,
the lower ends of the suspension pieces 31 are fixed to the base
frame 30 at each of the four corners and extend beyond the outside
limits of the base frame 30 and, therefore, the overall exterior
dimensions become much larger. Also, the use of such a separate
base frame 30 and individual suspension pieces 31 significantly
increases the total weight of the compressor unit. Furthermore, the
suction dust filter 5 and the suction muffler 6 are attached to the
side of the motor 3 so that they are not in the way during
maintenance inspection of the equipment, but the outer shape of
unit 1 becomes even larger. In addition, since the attachment
position of each suspension piece 31 cannot be removed because of
various limitations. In addition, the vibration-proof flexible
washers or dampeners 21, which are situated between the suspension
pieces 31 and the underside of the car floor 2 are unevenly
distributed. Further, the motor 3 and the compressor 4, which are
the major sources of the vibration conveyed to the base frame 30
and the suspension pieces 31, are remotely located; therefore, the
vibration-reducing action is minimal. Also, since the sizes of the
motor 3 and the compressor 4 are different, a shim, spacer or the
like must be used to adjust the height of each of the bases 32 on
the base frame 30 to align the interconnecting shafts. As a result,
the assembling of the unit and the centering and shim adjustment
requires an excessive amount of time. This, along with the fact
that it requires a separate base frame 30, as well as long
suspension pieces 31, makes the overall cost of the prior art unit
1 relatively high.
DETAILED DESCRIPTION OF THE INVENTION
The invention was conceived in order to alleviate the
above-mentioned shortcomings. The purpose of this invention is to
offer a unique railroad car air compressor unit in which a base
frame is not necessary, and in which the dust suction filter and
the suction muffler can be assembled in a shape so that they do not
extend beyond the outside limits of the compressor and motor
confines. Further, the suspension is a balanced structure which can
be positioned close to the motor and the compressor. Thus, the
centering operation is relatively simple and easily accomplished.
Accordingly, the unit is compact and lightweight, and has low
inertial vibration and low noise production. and is economical to
manufacture and assemble.
In practice, the shafts of the motor and the compressor are coupled
together, and the housings are interconnected by an intermediate
hollow mounting member, which has an outer dimension or diameter
that is smaller than the outer dimensions or diameters of the
housings of the motor and the compressor. The hollow mounting
member has an open end portion having an axially extending flange
which cooperates with a matching section formed on the motor
housing and/or the compressor housing. The rotating shaft of the
motor and the crank shaft of the compressor are interconnected by a
coupling member which is located inside of the intermediate hollow
mounting member. The suction dust filter and the suction muffler
are joined by a pressure connecting conduit and are mounted in a
facing position in the space between the motor and the compressor.
The motor and compressor are hung by a pair of suspension pieces
which are attached to the underside of the floor of the railroad
car by suitable vibration-absorbing members.
By employing the techniques and methods as described above, the
entire weight of the unit can be appreciably reduced and the
imparted vibrational forces can be perceptibly decreased since the
motor and the compressor are directly suspended without the use of
a base frame, and since the suspension pieces are relatively short
and compact. Moreover, since the suction dust filter and the
suction muffler are situated and mounted in assigned spaces which
are formed between the adjacent ends of the motor and the
compressor, they do not extend beyond the outer limits of the motor
or compressor housings. Therefore, the filter and muffler do not
form obstructions during maintenance inspections of the equipment.
Furthermore, the intermediate hollow mounting member is installed
to fit a matching or congruous section which is formed concentric
to the shaft of the motor and the compressor, therefore, centering
and aligning can be easily achieved.
Referring now to the drawings, it will be appreciated that the
following is an explanation of an actual embodiment of the
invention in which reference is made to FIGS. 1a, 1b, and 1c. The
various parts or elements which are the same as those of the prior
art described above are identified by the same reference numbers,
and their detailed explanations have been omitted. As shown, the
railroad car air compressor unit 1 of the subject embodiment is
also suspended from beneath the floor 2 of the railroad vehicle or
car and mainly includes an electric motor 3, an air compressor 4, a
suction dust filter or strainer 5, a suction muffler or silencer 6,
and an intermediate flanged hollow mounting member 7, which
interconnects and joins motor 3 and the compressor 4 together so
that the suspension pieces 8, 9, which jointly suspend the motor 3
and the compressor 4 beneath the floor 2 of the railroad car. It
will be seen that the outside dimension or outer diameter of the
intermediate hollow mounting member 7 is smaller than the outside
dimensions or outer diameters of the housings of the motor 3 and
the compressor 4. The open areas 10 are used for heat dissipation.
The open areas 10 extend from the top to bottom of the unit. As
shown in FIGS. 1a and 1b, the left end of the top side of the
compressor 4 has one suspension piece fixed to the crankcase 11 of
the compressor 4, and the right end of the compressor 4 includes an
annular flange 12 which is provided with a number of bolt holes.
The outer left end of the motor 3, which faces to the compressor 4,
is provided with the projection collar 14 which is formed to be
concentric with the rotational drive shaft 13.
The motor 3 and the compressor 4 are connected by fitting the
circular projection 14 into the flanged end of the intermediate
hollow mounting member 7 and being secured to the motor housing 3
by bolts 15. It will be seen that the rotation shaft 13 of the
motor 3 and the crankshaft 16 of the compressor 4 are connected
together by a coupling member 17. As shown, the suction dust filter
5 and the suction muffler 6 are fixed to one leg of mounting
brackets 18 which are disposed and secured to opposite sides of the
intermediate hollow mounting member 7. That is, the open spaces or
areas 10 formed between the motor 3 and the compressor 4 provide a
convenient spot for mounting the filter 5 and muffler 6 to the
bracket 18 which has another leg secured to outside surfaces of the
hollow mounting member 7. The lower end of the suction dust filter
5 and the suction muffler 6 are connected by the connecting conduit
or line 19 running underneath the intermediate hollow mounting
member 7. The one leg of bracket 18 is secured to the sides of the
intermediate hollow mounting bracket 7 by bolts 20 and the other
leg of the bracket 18 is fastened to the suction dust filter 5 and
the suction muffler 6 by being welded thereto.
The configuration of the intermediate hollow mounting 7 is not
limited to the specific design of the illustrated embodiment as
shown in FIGS. 1a, 1b, and 1c. It can be constructed in such a
manner that a flange may be formed on both ends which may be fitted
onto two projections 14 and connected with the bolts 15. The
projections 14 are preferably concentric to the shafts 13 and 16
and are formed on the outer facing end surfaces of the motor 3 and
the compressor 4.
Alternatively, the intermediate hollow mounting member 7 can be a
structure in which one side end is fixed or forms one piece with
the adjacent end bell of the motor 3 and the other end has a flange
12 which fits onto the projection 14 which is formed concentric to
the crank shaft 16 on the outer surface of the crankcase 11 of the
compressor 4 which faces the motor 3. Furthermore, the centering
operation can be accomplished by providing a plurality of fitting
pin holes instead of the projection 14. The suspension piece or
member 8 for the motor 3 is fixed to the center of the top or upper
outer surface of the motor housing 3 and is connected to the
underside of the car floor 2 by bolts 22 and by vibration-proof
flexible washers 21 or rubber dampeners which are located at both
ends. The suspension piece or member 9 for the compressor 4 is
fixed to the back end of the top or upper outer surface of the
crankcase 11 of the compressor 4 and is connected to the underside
of the car floor 2 by bolt 22 by vibration-proof flexible washers
or resilient dampening bumpers 21 which is centrally located
thereon. The attachment of each suspension piece 8, 9 to the
underside of the car 2 can be made by either a one-point
connection, or a two-point connection or more. Therefore, the
number of connecting points provided by the suspension pieces 8,9
and the underside of the floor of the car 2 should be more than
two; however, two to four points are the desirable range.
In the invention described above, since the motor and the
compressor are rigidly fixed as a unitary structure by the
intermediate hollow mounting member and the motor and the
compressor are suspended directly under the car floor by the
suspension pieces, a base frame is not necessary and the length and
number of the suspension pieces is reduced, so that the entire
weight of the unit is appreciably reduced. Also, since the spaces
between the motor 3 and compressor 4 are designed to accommodate
the suction dust filter and the suction muffler form a balanced
structure.
In viewing FIG. 2b, it will be seen that the filter and muffler do
not extend beyond the outside bounds of the unit, so that the
amount of space occupied by the unit as well as its balance are
improved thereby resulting in an extremely good design.
Furthermore, since the centering operation is relatively simple and
easy, the problems due to improper centering or increased vibration
are virtually eliminated. In addition, since the assembly time is
significantly reduced, the production costs can be greatly
decreased.
Further, the suspension pieces are connected directly to the motor
or the compressor housings which cause the most vibration so that
the connecting positions of these suspension pieces to the
underside of the car floor can be chosen freely. Therefore, it can
be installed in such a way that each suspension piece receives an
equal load, and the action of preventing vibration of the
vibration-absorbing material is increased. Therefore, the vibration
of the entire unit decreases and, as a result, the breakdown ratio
decreases and durability improves.
It will be understood that various alterations and changes may be
made by those skilled in the art without departing from the spirit
and scope of the subject invention. Therefore, it will be
appreciated that certain modifications, ramifications, and
equivalents will be readily apparent to a skilled artisan and,
accordingly, it is understood that the present invention is not to
be limited to the exact embodiment shown and described but should
be afforded the full scope and protection of the appended
claims.
* * * * *